Power is required for network processing systems, and these power requirements can be significant where a large amount of network processing circuitry is included within a network processing system. Further, airflow is often used to cool network processing systems that have high power requirements.
FIG. 1 (Prior Art) is a block diagram of an embodiment 100 for a prior network processing system having brackets 122 and 126 for power entry. An insulated power feed cable 120 has an internal conductor that is bolted to the rear side of a chassis 102 using bracket 124, and insulated power return cable 124 has an internal conductor that is bolted to the rear side of a chassis 102 using bracket 126. As shown by arrows 108/110, the airflow generated by the fan assembly 104 is pulled into the front of chassis 102, passes from the top part of chassis 102 through the network processing circuitry 106 into the bottom part of chassis 102, and exits the rear of chassis 102. It is noted that the fan assembly 104 can also be configured to push air through the chassis 102 rather than pull air through the chassis 102 as shown in FIG. 1. The airflow would then travel the opposite direction from the direction shown in FIG. 1.
The power entry provided by brackets 122/126 is cumbersome because screws that secure the brackets 122/126 to the chassis 102 must be accessed by technicians managing the network processing system. In addition, as high power is being fed and returned by cables 120/124, the relative ease that conductive brackets 122/126 can be touched by the technician or a tool creates safety problems. Further, fuses associated with the power entry brackets 122/126 will typically be placed within the chassis 102, and this placement can make it difficult to access the fuses. Still further, because the brackets 122/126 are secured to the back of the chassis 102, the power feed/return cables 120/124 will tend to pass over the fan assembly 104 and interfere with airflow through the chassis 102. Even if the connection locations for brackets 122/126 are moved to avoid interference with fan assembly 104, the power feed/return cables 120/124 will still tend to interfere with another chassis below or above chassis 102 when multiple network processing systems are stacked, for example, within a rack. Further, this configuration requires increased rack spacing between multiple stacked modules within a rack and make more difficult the removal/insertion of various modules within a rack.